In connecting an air pump hose in an airtight manner to a tube valve it is usual to clamp an end part of the hose to the threaded valve tube. However, it is difficult to always do so, particularly with valve types presenting no bearing surface for the clamp. Therefore connecting pieces have been developed which can be screwed on the threaded valve tube to create an artificial bearing surface. However, the known fixation clamps present the disadvantage, that said connecting pieces cannot be affixed to them and therefore will usually not be disposable when they should be used.